The present invention relates to fluid driven pumps and portioning check valves, for example, useful with such pumps. More particularly, the invention relates to fluid driven pumps which employ flexible diaphragms to obtain pumping action and to portioning, preferably adjustable portioning, check valves useful to control fluid flow, such as the flow of fluid pumped by the present pumps.
Fluid driven pumps are well known in the art for pumping other fluids. For example, a working fluid, such as compressed air, can be used to power a piston or expand a diaphragm thereby creating a pumping force which can be used to pump another fluid. In many instances, such pumps require that the flow rate of the working fluid be controlled so as to control the flow rate of the pumped fluid. Such control mechanisms can be relatively complex and can require relatively frequent maintenance.
In many instances, a concentrate material is pumped at a set or controlled rate after which it is mixed with a set amount of diluent, for example, liquid water, to provide a composition which is used for a valuable purpose, such as feeding or otherwise treating plants, as well as many other applications. Systems for producing such mixed compositions often include relatively sophisticated metering pumps to insure that the proper amount of concentrate is combined with the desired amount of diluent.
It would be advantageous to provide fluid driven pumps which are straightforward and effective, such as pumps for concentrates useful in combination with diluents.